1. Field of the Invention
This invention relates in general to speed monitoring and in particular to speed monitoring which utilizes digital circuits entirely in a clock/counter mode.
2. Description of the Prior Art
A shortcoming of the known prior art has been the use of delay flops circuits in determining whether a rotating member has developed sufficient speed to sustain a flying magnetic read/write head. Discrete circuit components (i.e. RC network) have been utilized with prior art delay flop circuits for developing their period of operation. This circuitry has not proved entirely satisfactory since the delay flop period has drifted due to aging and temperature variations. Consequently, adjustments have been necessary in known prior art systems in order to maintain the delay flop circuit in proper operating condition. The accuracy drift due to aging and temperature as well as the need for adjustments has not been entirely satisfactory.